Processes of removing anions from liquids



Patented May 1949.

UNITED STATES mewworms rnoosssns F nnmovmc iimonsrnoif moums t ILennfll't A. Lundberg, Stamford, and James a. Y

- Dudley, Cos Cob,.Conn.,

Gy'anamid Company, New York, N. Y., a cornotation of Maine No Drawing.Original asslgnors to American application September is.

1945, Serial No. 616,644. Divided and this application September 15,1945, Serial No. 616,645

esses of purifying fluid media by means of such resins. I

Epichlorohydrin has previously been condensed with amines to formwater-soluble products useful in the dyeing and printing arts. In theproduction of such substances 1 mol of epichlorohydrin is reacted with 1mol of a primary amine.

An object of the present invention is to provide a resinous materialwhich is insoluble'in water and which is suitable for removing anionsfrom water and other fluid media.

Another object of the present invention is to provide an improvedprocess for removing anions from water and other fluid media.

Still another object of the present invention is to prepare an anionactive resin from epichlorohydrin and a polyamine.

A further object of the present invention is to provide a process ofproducing resinous materials suitable for the removal of anions fromfluid media.

The first, third, fourth and other objects are attained by condensing analpha-chloro-beta,- gamma-epoxy organic compound, e. g., epichlorohydrinwith an'alkyiene polyamine in the form of the free base, by bringingthem together in a molar ratio of at least 2:1, respectively.

The second object is attained by contacting a fluid containing anionswith an insoluble resin prepared in the manner described above. a

The following examples in which the proportions are in parts by weightare given by way 0 illustration and not in limitation.

ExAmLE 1 Parts Epichlorohydrin (30 mols) 2,776 Tetraethylene pentamine(10 mols) 1,890 Water 5,500 Sodium hydroxide (5 mols) 200 Thetetraethylene pentamine is charged into a suitable reaction vesselprovided with an agitator and a. means for cooling the vessel. 4500parts of the water are added to the tetraethylene pentamine and theresulting solution is cooled to about 3 C. The epichlorohydrin isaddedslowly over a period of 30 to 70 minutes or more while the reactingmixture isbeing continuously agitated. Afterall the epichlorohydrin has.been added the resulting syrup is maintained at a temperature belowabout C. for 1 hours or more. The syrup is then permitted to warm up toabout room temperature over aperiod of 45 for the removal of anions fromfluid media and to pro'ce solved in 1000 parts of the water is added.The

resulting solution is heated for example by passing steam into a jacketsurrounding the reaction vessel for about 5 minutes, thereby causin thesyrup to gel. The gel is broken up in small pieces and cured in traysplaced in an ovenat a temperature of about 95405 C. for 17-18 hours. Thecured resin is ground and screened and th 20-40 mesh material is placedin asuitable bed through which water containing 0.004 N sulfuric acidand 0.002 N HCl is passed. The resin removes the acid from the water andits capacity is found to be equivalent to 24-27 kilograins (hereinafterabbreviated kgrs.) of calcium carbonate per cubic foot of resin; Theresin has a density of about 14 lbs/cu. ft.

After regeneration'the exhausted resin is used to remove acid from wateragain and this cycle maybe repeated 100 or more times without loss ofcapacity. No decrease in capacity is found with repeated cycles wherethe water-containing acid is at a temperature of about C.

ExAm'Lr: 2 Parts Epichlorohydrin (25 mols) 2,313 Tetraethylene pentamine(10 mols) 1,890- Water 4,300

These substances reacted in the same general manner as described inExample 1 except that no sodium hydroxide is added. A resin havin acapacity equivalent to about 21.4 kgrs. of calcium carbonate per cubicfoot-of resin is ob- 'The sodium hydroxide is dissolved in 1000 parts ofthe water and the substances reacted in the manner described in Example1 to produce a resin having a capacity equivalent to about 16.7 kgrs. ofcalcium carbonate per'cubic foot of resin and it-has a density of about10.4 lbs. /cu. ft.

/ EXAMPLE 4 i i Parts 'Epichlorohydrin (40 mols) 3,700 Tetraethylenepentamine (lilmols) 1,890 Water 6,000

Sodium hydroxide (15 mols) 600 Exmu:

Parts Epichlorohydrin (45 mols) 4,163 Tetraethylene pentamine mols) 1,890 Water 6,500 Sodium hydroxide mols) 800 The sodium hydroxide isdissolved in the water and the reactions carried out as described inExample 1. The product has a capacity equivalent to 19.2 kgrs. ofcalcium carbonate per cubic foot of resin and it has a density of 11.1lbs./ cu. ft.

EXAMPLE 6 1 Parts Epichlorohydrin (30 mols) 2,776 Tetraethylenepentamine (10 mols) 1,890 Water 4,520 Sodium hydroxide (10 mols) 400 Thesodium hydroxide is dissolved in 870 parts of the water and thereactions carried out as described in Example 1. The product has acapacity equivalent to about 22.3 kgrsrof calcium carbonate per cubicfoot of resin and it has a density of about 10.5 lbs/cu. ft.

Exsmrm 7 Parts Epichlorohydrin (30 mols) V 2,776 Tetraethylene pentamine(10 mols) 1,890 Water 5,360 Sodium hydroxide (20 mols) 800 The sodiumhydroxide is dissolved in 1710 parts ofthe water and the reaction iscarried out as described in Example 1. A product having a capacityequivalent to 14 kgrs. of calcium carbonate per cubic foot of resin andhaving a density of 9.7 lbs/cu. ft. is obtained.

Example 8 A resin is prepared in accordance with Example 2 except thatit is cured under different conditions. In this example the moist gelafter being broken up is placed in a vessel with a reflux condenser anda jacket through which hot oil is circulated. The resin is heated inthis vessel under reflux for about 17% hours at 95-105 G. and,thereafter the resin is air-dried. It is ground immersed in water andscreened wet to 20-40 mesh size. This product has a capacity equivalentto 15.3 kgrs. per cubic foot of resin and a density of 12.1 lbs./ cu.ft.

Exsmm 9 EXAMPLE 10 Parts Epichlorohydrin (30 mols) 2,776 Ethylenediamine (10 mols) 600 Water 2,250 Sodium hydroxide (20 mols) 800 Thesodium hydroxide is dissolved in 1000 parts of the water, and thesesubstances reacted in accordance with the procedure of Example 1. Theproduct has a capacity equivalent to 13.9 kers. of calcium carbonate percubic foot of resin and it has a density of 11.9 lbs/cu. ft.

EXAMPLE 11 Parts Epichlorohydrin (25 mols) 2,313 Diethylene triamine (10mols) 1,030 Water 3,750 Sodium hydroxide (7.5 mols) 300 The sodiumhydroxide is dissolved in 750 parts of the water and the reactioncarried out as described in Example 1. The product has a capacityequivalent to 20.7 kgrs. of calcium carbonate per cubic foot of resin,and it has a density of 18.1 lbs/cu. it. of resin.

EXAMPLE 12 7 Parts Epichlorohydrin (25 mols) 2,313 Di(3aminopropyD-amine (10 mols) 1,310 Water 3,000

These substances are reacted in accordance with Example 1 except that nosodium hydroxide is added. The capacity of the product is equivalent to13.6 kgrs. of calcium carbonate per cubic foot of resin and the densityis 21.9 lbs/cu. ft.

EXAMPLE 13 Parts Epichlorohydrin -(25 mols) 2,313 Polyethylene polyaminemixture (10 mols)--- 1,181 Water 4,250 Sodium hydroxide (7.5 mols) 300The polyamine mixture contains about 75% diethylene triamine, 15%triethylene tetramine and 10% tetraethylene pentamine. The sodiumhydroxide is dissolved in about 750 parts of the water, and the reactioncarried out in accordance with Example 1. An anion active resin having acapacity equivalent to 18.3 kgrs. of calcium carbonate per cubic footresin is obtained, and the product has a density of 14.3 lbs./ cu. ft.

EXAMPLE 14 Parts Ep-ichlorohydrin (30 mols) 2,776 Polyethylene polyaminemixture (10 mo1s).. 1,181 Water 4,250 Sodium hydroxide 240 Exmrm 15Preparation of a polyamine Parts Tetraethylene pentamine 284Trimethylene dibromide 202 Water 1,100 sodium hydroxide 40 .faceaeea sThe tetraethyl'ene pentamine was iplaced in a with the abovcprocedure isin a suitable suitable reaction vessel provided with a means. reactionvessel and 291 parts of epichlorohydrin heating the vessel, such as asteam Jacket. The added thereto, and the reaction and further reactionvessel is also provided with an agitator. processing is carried out inaccordance with The tetraethylenepentamine is heated to about Example 1.anion active resin having a 85 C. while the trimethylene dibromide isadded capacity equivalent to 23.8 kgrs. of calcium carslowly whilemaintaining the temperature at bonate per cubic ioot of resin and havinga denabout 85-90 C. After all the trimethylene disity of l'zA'lbs/cu.ft. is obtained.

bromide is added the resulting viscous syrup is heated for aboutone-half hour or more. Thev 1o syrup is dissolved in one thousand partsof the- Part8 water and then cooled to about 5 c. The sodiumTetraeflwlene W m hydroxide is dissolved in 100 parts of the water.water v and is added in order to form the free base of Sodium -"fpolyamine. Theoretically, a linear polyamine 15 Ethylene dichloride 347containing 15 nitrogen atoms per molecule should 1 A o utio ontainingthe tetraethylene pen-' be formed, but it is believed that thecomposition taming parts of water n t sodium is a mixture containingsome polyamines having hydroxide is heated m a suitable reaction vesselfewer than 15 nit o n atoms a Well some provided with a means forheating and cooling,

polyamines having more than 15 nitrogen atoms and provided th anagitator, The solution is per molecule. heated to about 85 C. and theethylene dichloride is then added slowly at such a rate that thePreparation of resin temperature does not rise above 95 C. During Thepolyamine solution prepared in accordance the addition of the ethyl n ielor de an ex-' with the foregoing is maintained at about 5 C. 25othermic reactionoccurs which continues for a and agitated, while 254parts of epichlorohydrin f short time after all of the ethylenedichloride is is added slowly. The resulting reacting mixture added.After the exothermic reaction subsides is kept at about 5 C. for about 1hour, and then the resulting Sy pmil-ted for about hour the mixture isgradually heated by means of tocomplete the reaction. During thereaction steam until it gels to form a firm opaque orange 3i) aconsiderable amount of sodium chloride sepaproduct. The resulting gel isbroken up and rates and this may be dissolved by adding 1500 cured,ground and screened in accordance with parts of the-water.

Example 1. The product has a capacity equivalent to 26.5 kgrs. ofcalcium carbonate per cubic m foo of resin nd a densi of about 12.41 t.v d r t a w f The polyamine solution prepared in accordance Exmrni: 16with the foregoing procedure is cooled to a temperaturebelow about 5 C.and 847 parts or mlwmme epichlorohydrln are added slowly with agitation.

Parts Tetraethylene pent-amine 2 4 .4 t about 0! an hour thetempera-hire Trimethylene (bromide 151 the reacting mixture, Permittedto rise d water 1,10 ualiy, and then the syrup is heated by means Sodiumhydrmzidp 30 of steam which causes the syrup togel immediately to form atransparent rigid material. The

These substances are reacted in the manner resumn e1 15 broken u andfurther recessed described in Example 15, the sodium hydroxide mthe igdescribed Example 1 produce being dissolved in 100 parts of the water toprea anion active matrial having a capacity of pareapolyamine solution,the polyamine of which. 3 k-grs of calcium carbonate per cubic foot ofshould theoretically contain 10 nitrogen atoms rsin a density aboutlbsJcL it per molecule.

Preparation of mm v Parts The polyamine solution prepared in accordancecn hy h --e---- 920 with this example is condensed with 277 parts of1611B 1118-1111116 (5 111015) 43 epichlorohydrin in accordance withExample 1 to ja e J o I i 1.650 form an anion active material having acapacity "sodiulnlhydmlides 206 equivalent to kgrs' of calciumcarbonatelper- To'afs'olution" of" the ethylene diamine in about cubicfoot resin and having a density 12 partsgofi the water, theepichlorohydrin is lbs/cu. it. I v I 7: oadded- Exmrir i7 IPreparationoj polyamine o m g. Anopaque oil separates and then esOlidforms. After about 1% hours, th reaction mixture is heated by means ofsteam rfl hy D m 284v ermicreactibn follows and the -solidwhlchTrimethylene dibmmide uspended in'liquid dissolves'to yield a clearWater ryellow syrup which is about neutral. The syrup Sodium Y chilledand a solution containing the sodium The .polyamine solution is preparedby reacting hydroxide 1114 part f th W ter is added these substances inthe manner described in'Ex-i; ofslowlyr After about 30 minutes, thesyrup is ample 15, the sodium hydroxide being dissolved heated by means:of steam and 8- 8 1 *f rm in slowly while maintaining the temperaturesurrounding the reaction vessel. An

in 100 parts of the water and the 750 parts of about 20 minutes. The.resulting soft, orange,

water being used in place of the 1000 parts of rubbery gel is cured inaccordance with the water usedinExampl'e 15. j y

The polyamine solution prepared in accordance :ha'sa capacity equivalentto 18.5 kgrs. or calcium procedure described in'Example 1. The product.density of about 14 lbs./cu. ft.

- Example 19 is repeated except that the epi- 'chlorohydrin is added tothe ethylene diaminesolution at 65-70 C. No heat is applied as theregulated by the rate of additionof the epichloro-v hydrin to theethylene diamine solution. After the addition of the epichlorohydrin tothe ethylene diamine is complete. the exothermic reaction subsides andthe reaction mixture is then heated by means of steam to produce 'aclear syrup which is neutral after about minutes. After the addition ofthe sodium hydroxide solution, the reaction mixture is again heated bymeans of steam to produce a clear, orange, glossy gel. Aftervthis gel iscured and granulated in the manner described in Example 1, it is foundto have a capacity equivalent to about 22.2 kgrs. of calcium carbonateper cubic foot of resin and to have a density of about 171bs./cu. ft.

Other polyalkyiene polyamines may be substituted for part or all ofthose used in the preceding examples. Furthermore, mixtures of two,three, four, five, seven or any other number of polyamines may beemployed.

Examples of suitable polyamines include 1,3-'

of large numbers of molecules of ammonia to ethylene dibromide orethylene dichloride and the like may be used.

It is essential that the molar ratio of epichlorohydrin to the polyaminebe at least about 2:1 when the two substances are brought together inorder to obtain insoluble resins. There is no maximum amount ofepichlorohydrin which may be used but generally it should not exceed amolar ratio of 5:1 or with polyamines having more than five amino groupsthe ratio should not be greater than 1 mol of epichlorohydrin for eachamino group in the polyamine. While proportions of epichlorohydrinlarger than those mentioned may be used if desired, it will generally beundesirable since this will ordinarily reduce the capacity of theresulting resins. On the other hand the use of higher ratios ofepichlorohydrin to. polyamine may be advantageous for economic reasons.

While the addition of a strong alkali, such as sodium hydroxide, is notessential, it is often desirable when the molal ratio of epichlorohydrinto polyamine is 3:1 or greater. The higher the ratio of epichlorohydrinto polyamine, the slower the reaction and, therefore, in order to-speedup the reaction, the use of some strong alkali to react withhydrochloric acid, which is set free in the reaction, is helpful. On theother hand the use of alkali, particularly in large quantities isundesirable, since it reduces the structural rigidity or resistance ofthe attrition of the product. The molar ratio of alkali to theepichlorohydrin is desirably between about 1:10 and 1:1. Any strongalkali may be used which will not condense "8 with the epichlorohydrin.Examples of suitable substances are sodium hydroxide, sodium carbonate,potassium hydroxide, potassium carbonate,

lithium hydroxide, calcium hydroxide, etc.

Instead of epichlorohydrin other substances having an alpha-chloro-beta,gamma epoxy arran ement r l reaction is exothermic and the temperatureis g a e suitab e for reaction with poly amines in accordance with thisinvention to produce anion active resins. Among these some examples arecompounds of the following general formula:

R ct-ca-ca ca where R is the same or different organic radicals orhydrogen. Preferably, the R groups contain pyridyl, furyl, etc.

no strong acidic groups such as sulphonic acid EIOLIDS but any organicradicals may be used since the R groups are not important. It isimportant that the chloro and epoxy groups be in the positionsindicated. The R groups may, for example, be CHa--, CzHs--, C:H'1, CtHu,CsHn, ClilH2l-, phenyl, benzyl, tolyl, xylyl,

Among these some examples are:

The use of a major proportion of substances such as 1,3-dichloropropanol-2 for reaction with alkylene polyamines alone or along with thealpha-chloro-beta, gamma epoxy compounds is disclosed and claimed in a'copending applica- I herein. andwhichare covered in separate appii-lcations the following are a few example 1 C1-OiIrCE-CHg-Cl While thepresent invention does not cover the use of a major proportion or all ofone of the compounds in the foregoing list of substances for reactionwith an alkylene polyamine-nevertheless, minor molal proportionswithrespect to the total substances reacted with the polyamine any desiredsolvent which does not react with the reactants or the reaction productssuch as -zation' etc.

waterimetha'noi ahead; the mono-methyl 'oir mono -ethyl etherfsofethylene glycol, etc.}-.,While 'nvenienttoad'd :the epichlorohydrintothe polyamine the orderoff addition may be reversed.

. 5* 1 polyamine resultsimainly' in the rupture of the epoxy'ring andthe formation of a Z-hydrox'y-B- The initial "reactionfof=epichlorohydrin with a chloropropyl amine. Thisreaction is quiteexothermic and ,for this reason .the epichlorohydrin is mixed with thepolyamine" by adding one to the other slowly, in order to.avoidoverheating.

'Furthermore,- the polyamine and the reaction mixture is preferablycooled for the same reason. However, the reaction may be carried out atordinary room temperatures and/or even at elevated temperatures if theepichlorohydrin is added to r the polyamine slowly in order to avoid anyof the dimculties which may arise from overheating.

,The dimculties which may arise are practical difliculties such as'rapidboiling of the reaction mixture, loss of the reactive materials byvapori- In other words, the reaction temperature is not critical and,therefore, the temperature may be varied from about 0 C. .up to 70 C. oreven higher. However, in the condensetion of the epichlorohydrinwith apolyamine the reaction mixture is preferably cooled to permit therupture of the epoxy ring and to prevent alkylation through the chlorogroups. The products formed in the initial reaction are watersoluble.Apparently the condensation of 3 mols of epichlorohydrin with 1 mol oftetraethylene pentamine under the conditions used herein may berepresented as follows:

In the second stage usually when the reaction mixture is heated, (ormore slowly if not heated) self-alkylation occurs between the chlorogroups and the amine groups bearing hydrogen to form athree-dimensional, insoluble resin. This reaction may occur directly inaccordance with the following scheme:

or it may occur indirectly where the first step is the formation of anepoxy ring followed by condensation with the amine in accordance withthe following illustration:

In any event the structure will probably be the same and this structuremay be repeated as foll1 lows on the basis 01' the reaction or three ofthe units formed in the initial condensation shown above. The structurewould then be: 1

N-CHrCHg-NCHg-CHrN-CBrCHrN-CHrCHg-N In view of the foregoing it isapparent that the resinous materials formed in accordance with thisinvention are condensation products and, accordingly, the curing ofthese resins is by condensation, and this occurs without the use ofcatalysts. Inasmuch as hydrochloric acid is set free alkali may be addedas pointed out heretofore to absorb excess acid. The heat treatmentwhich is given to the resin is a final step of the process and, althoughit has sometimes been called curing in the discussion, it is primarily adrying operation. During this heattreatment the gel structure of theresin appears to be altered somewhat inasmuch asconsiderable shrinkageoccurs. When the resin is rewet it does not swell to the same volume asit did before the heat-treatment, although the resin still swells tosome extent.

The final heat-treatment or curing of the resin in accordance with ourinvention is preferably carried out at a temperature of 95-105 C. in dryheat, although other conditions may be used including temperatures from50 up to about 125 C. or higher.

The anion active resins may be activated or regenerated by means ofdilute alkaline solutions, such as for example, 0.1-% aqueous solutionsof sodium hydroxide. sodium carbonate, etc.

The resinous materials produced in accordance with this invention aresuitable for the removal of all kinds of acids and anions in generalfrom fluid media. They may be used to extract the strong mineral acids(preferably in relatively low concentrations), organic acids such asacetic acid, oxalic acid etc., from water and organic in the waterpurification art resins should have a suiliciently low solubility thatthey will not dissolve very rapidly by the solution to be treated.

- Thus, water should not dissolve more than 1 part liquids. The anionsof salts such as chloride ion,

from ammonium chloride, or a sulfate ion from ammonium sulfate may beremoved by means of the resinous products described herein.

The anion active resins are useful for many purposes, examples of whichare the removal of acid from water, the removal of acid from alcoholicsolutions, the purification of sugar juices, the purification of pectin,the removal of acid from aqueous formaldehyde solutions etc. While theresins are especially suitable for the removal of anions from aqueousmedia they may be used to extract acids or anions from fluid media otherthan water, and they may even be used for the extraction of acids fromgases. The resins may be used as absorbents for plant nutrients and assuch may be used as media for growing plants or as a means for applyingnutrients to the soil.

To be sufficiently insoluble for practical use of resin in 1000 parts ofwater when passed through a bed of resin (after the first cyclecomprising an activation, exhaustion and reactivation oi the resin).

While the mechanism of the reactions involved in the production of theresins described herein is believed to take place in accordance with thediscussion set forth above, it is to be understood that we are not to bebound thereby.

This is a division of our copending application, filed concurrentlyherewith, Serial No. 616,644,

entitled Anion active resins and processes of producing same.

We claim:

1. A process which comprises contacting a liquid medium containinganions with a waterinsoluble granular resinous material obtained by aprocess comprising a step of bringing together analpha-chloro-beta,gamma-epoxy hydrocarbon and at least one alkylenepolyamine in the ratio of at least 2 mols of said hydrocarbon per mol ofpolyamine, the number of mols of said hydrocarbon being not greater than1 mol for each amino group of said polyamine, permitting the resultingcondensation product to gel, curing the resulting gel by heating at 50C. to about C., and granulating the gel, said granular resinous materialbeing of such low water solubility that water will not dissolve morethan 1 part of resin in 1,000 parts of water when it is passed through abed of resin after the first cycle comprising an activation, exhaustionand reactivation of the resin, and separating said medium from saidmaterial.

2. A process as in claim 1 wherein said polyamine is di(3-aminopropyl)-amine.

3. A process as in'claim 1 wherein said alphachloro-beta,gamma-epoxyhydrocarbon is epichlorohydrin.

4. A process as in claim 1 wherein said liquid medium is an aqueousmedium.

,5. A process as in claim 1 wherein said polyamine is a polyethylenepolyamine.

6. A process as in claim 1 wherein said polyamine is tetraethylenepentamine.

7. A process which comprises passing an aqueous medium containing anionsthrough, and in contact with, a bed of a water-insoluble, granular,resinous material obtained by a process comprising bringing together atleast 2 mols of epichlorohydrin with 1 mol of at least one polyalkylenepolyamine to form a gel, heating the gel thus obtained at 50 to about125 0., and granulating the gel, the number of mols of saidepichlorohydrin being not greater than 1 mol for each amino group ofsaid polyamine, said granular resinous material being of such low watersolubility that water will not dissolve more than 1 part of resin in1,000 parts of water when it is passed through a bed of resin after afirst cycle comprising an activation, an exhaustion and a reactivationof the resin.

8. A process of removing acid from an aqueous medium which comprisespassing an aqueous medium containing acid through, and in contact with,a granular, water-insoluble, resinous material obtained by a processcomprising bringing together at least 2 mols of epichlorohydrin with 1mol of at least one polyalkylene polyamine to form a gel, heating thegel thus obtained at 50 to about 125 'C., and granulating the gel, the

Q anemone,

number of mols of said epichlorohydrin being not greater than 1 me] foreach amino group of said polyamine, said granular resinous materialbeing of such low water solubility that water will not dissolve morethan 1 part ofresin in 1,000 parts of water when it is passed through abed of resin after a first cycle comprising an activation, an exhaustionand a reactivation of the resin.

' LENNART A. LUNDBERG.

JAMES R. DUDLEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number ,223,930 2,259,169 2,288,514 2,341,907 2,352,070 2,354,1722,366,129 2,388,235

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